Method of forming attachments for dentures



June 3, 1930. s. RICHARDSON 1,761,312

.METHOD OF FORMING ATTACHMENTS FOR DENTURES Filed March 3, 1927III/IIII/ Patented June 3, 1930 UNITED STATES PATENT OFFICE SIDNEYRICHARDSON, OF HOLLYWOOD, CALIFORNIA, ASSIGNOR TO ANNIE RICHARD- SON, OFLOS ANGELES, CALIFORNIA METHOD OF FORMING ATTACHMENTS FOR IDENTURESApplication filed March 3, 1927. Serial No. 172,414.

My invention relates generally to dental appliances, and morespecifically to a method of forming a readily detachable anchoringdevice or attachment for dentures, removable bridge Work, and the like,and the principle object of my invention is to provide a relativelysimple, and easily practiced method for producing an attaching devicethat is capable ofbeing readily applied to dentures,removable bridgework, and the like, and which device has great strength and rigidity andtherefore serves to very firmly retain the denture or removable bridgework in proper position within the oral cavity.

A further object of my invention is to provide an improved method offorming an attachment or anchoring device of the character referred to,which, with slight modifications may be utilized as a stress breakerextension for the attachment of certainforms of dentures. f

t will be understood that attachments produced in accordanqe with myinvention relates are necessarily relatively small in size and as thedentures or parts that are supported by the attachments are subject toconsid-- erable stress, the attaching means must necessarily have thegreatest possible degree of strength to resist the applied strains andstresses.

It is the purpose of my invention to form the parts of the attachment,and particularly the male member thereof, so that the strength of themetal of which the parts are formed, is utilized to the greatest degreein resisting the strains and stresses that may be developed while theattachments are in use. 3

With the foregoing and other objects in view, my invention consists inthe method hereinafter more fully described and reference being had tothe accompa'nyingdrawing, in which Fig. 1 is aperspective view of ablock of metal from which the male member of my improved attachment isformed.

Fig. 2 is a perspective view of the block of metal after the same hasbeen machined to proper shape] and before it has been dio'0 vided. I I

' I Fig. 8 is a perspective View of the box that Fig. 3 is a perspectiveview of the finished male member of my improved attachment.

Fig. 4 is a perspective view of the tube or cup that receives the heador body portion of the male member of the attachment.

Fig. 5 is a plan view of a denture that is provided with my improvedattaching devices and showing the latter anchored in abutment inlays.

Fig. 6 is a vertical section taken approxi mately on the line 66 of Fig.5.

Fig. 7 is an elevational view of the male member of the attachment andwhich is constructed to serve as a stress breaker extension.

receives the shank of the male member of the stress breaker attachmentand which box is anchored in a denture or removable bridge work.

Fig. 9 is a horizontal section taken through a denture that is equippedwith my improved attachment and showing a set screw that is utilized forsecuring the denture and its box to the shank of the male member of thestress breaker.

In the production'of the male member of the attaching device by myimproved method, I utilize a substantially rectangular block 10 of alloyor platinized metal that is very hard and tough and by machiningoperations, a'portion of the body of this block of metal on one sidebetween its ends is removed so as to form a substantially U-shapedmember, as illustrated in Fig. 2, and which member comprises parallelend portions 11, the lower ends of which are connected by a plate or web12. The member thus formed is now cut or divided by suitable means ata'centrally arranged transverse point, as indicated by the dotted line(I- in Fig. 2, thus producing two identical L-shaped members.

The rear or under faces of the two parts of the web or plate 12 are nowplaced in direct contact with each other and the outer portions, orthose portions remote from the end walls or members 11, are integrallyconnected by a suitable fusing, welding, or brazing operation and thusthe two parts of the web or plate 12 are united to form a substantially100 of a suitable tool to slightly spread the parts 11 of the head ofthe device in the event that it becomes necessary totake up any wear orplay that might develop between the head and the tube or sleeve in whichthe same is seated, and which condition n'iight exist as a result ofwear during extended use.

Inasmuch as the male member, comprising a shank 13 and head formed bythe parts 11, is milled from a solid block of metal, the molecules andfibers of the metal in all parts of the member retain their originalrelative positions, thus insuring greatest possible strength andresistivity to strains and stresses while the device is in service.

In the manufacture of the male member of the attachment, the slot 14 isbut one or two thousandths of an inch in width and therefore relativelylittle strength is sac'ri-' ficed by the formation of said slot.

The milling of the male member from a solid block of metal eliminatesthe necessity s for bending any portion of said member dur ing itsproduction, and which bending, it will be understood, necessarilydisturbs, stretches and expands the metal at the bending point and whichaction materially weakens the finished structure.

The tube or socket member that receives the head 11, and which isillustrated in Fig. 4, is

preferably formed of sheet metal such as platinum and said tube orsocket comprises a vertically disposed cup-shaped member 15 ofsufficient size to snugly receive the head 11 of the male member. Forthe accommodation of the projecting shank 10 of the male member, avertically disposed opening 16 is formed in the central portion of oneof the side walls of the tube or socket, the lower end of said openingbeing closed and the wall of the tube or socket immediately adjacent tothe edge of this opening 16 is increased in thickness to form asubstantially U-shaped reinforcing member 17 around said opening.

In view of the fact that the material from which the tube or socket 15is formed is relatively thin, it is necessary to reinforce the edges ofthe opening 16 in order to provide ample strength for that portion ofthe tube that is positioned immediately adjacent to the inner end of theshank 10 or that portion of said shank that is immediately adjacent tothe head 11.

In order to accommodate that portion of the reinforcement 17 thatextends across the bottom of opening 16, the lower portion of shank 13is cut away and thus the lower edge of said shank terminates in a planeslightly above the plane occupied by the under face of head 11.

The tube or socket 15 is permanently anchored in an inlay such as 18 andwhich latter is seated in the face of a tooth to which the denture orremovable bridge work is to be attached and the shank 13 of theattachment is firmly anchored in the body of the denture D or removablebridge work.

Thus when the parts of the attachment are properly formed and associatedwith the denture or removable bridge work and the teeth to which thelatter is detachably connected, the heads 11 of the attachments projectfrom the denture or removable bridge work and said heads are inserted inthe anchored tubes or sockets 15, thus providing a very firm andsubstantial connection between the denture or removable bridge work andthe teeth to which the same is anchored.

Where my improved attachment is constructed for use as a stress breaker,the shank of the male member of the device is formed at an anglerelative to the horizontal plane occupied by the head of said member andthus the stress breaker takes the form as illustrated in Fig. 7, withthe upper and lower edges of the shank 1O occupying planes within arange for 15 to 30 relative to a horizontal plane. These stress breakersare particularly designed for use in What are termed close bite cases.

The stress breaker box that receives the shank 13 and which isillustrated in Fig. 8, comprises a substantially rectangular shell 19formed of relatively thin metal, preferably platinum, with both endsopen and the size of said box being such as to receive the shank 13.This box is firmly anchored in any suitable manner in the body of thedenture or removable bridge Work.

Where it is desired to secure the shank of the male member within thebox 19 so as to permit said male member to have a limited degree ofrocking movement within the box and at the same time to retain the partsin proper position, a threaded aperture A is formed in the lingual orpalatal walls of the denture and box and a small set screw such as 20 isscrew-seated in the aperture A. The point of this screw passes throughthe aperture A in the box and bears against the adjacent face of theshank 13.

The position of the screw 20 is such, that it bears on the shank at apoint entirely beyond the inner end of the slot 14 in the head of thestress breaker. Therefore, said set screw has a firm bearing on the bodyof the shank and when expanding the head by insertion of a suitable toolin the slot 14, there is no binding on the inner end of the screw, forthe movement of the expanded portions of the device do not extendthrough the shank beyond the inner end of the slot therein. Thusfracture of the male member as a result of repeated spreading of thehead end thereof is minimized and the inner end of the screw 20 alwayshas bearing on that portion of the shank having the greatest thickness.An especially desirable feature of my invention is the formation of themale member of the attachment from a solid block of metal withoutbending or in any way disturbing the original molecular structure of themetal, for by so doing, the maximum strength of said metal in thefinished product is retained and which strength is highly desirable indevices of the character to which my invention relates, for said devicesare necessarily small and they are subjected to strains and stresses ofconsiderable de ree while in service.

Thus it will be seen that I have provided an attachment for removablebridge work, clentures, and the like, that is relatively simple inconstruction, inexpensive of manufacture,

and which will be very effective in performing the functions for whichit is intended.

It will be understood that minor changes in the size, form andconstruction of the various parts of my improved attachment forremovable bridge work, dentures, and the like, may be made andsubstituted for those herein shown and described without departing fromthe spirit of my invention, the scope of which is set forth in theappended claim.

I claim as my invention: The herein described method of forming anattachment for dentures which consists in cutting a solid block of metalto form a substantially U-shaped member, dividing said member on amedial line to form two identical L-shaped members, arranging said L-shaped members so that two of the legs thereof lie back to back and thenintegrally connecting portions of the legs of said L-shaped members soas to form a substantially T- shaped member.

In testimony whereof I aflix my signature. 5;) SIDNEY RICHARDSON.

